1. Technical Field
The present invention relates to a method for determining variations among multiple three-dimensional stone images extracorporeally, and more particularly to a method involving computing texture feature values of multiple three-dimensional stone images and determining variations among the images according to the texture feature values, and to a computer program using this method.
2. Description of Related Art
Wealth has a tendency to make people have high-oil, high-protein and refined diets, which are adverse to physical health and may incur illness. Among the most affected organs are kidneys that serve to remove waste products of metabolism from the human body. Kidneys are essential in the urinary system, and responsible for filtering out impurities from blood, maintaining fluid-electrolyte balance, and at last producing urine that then leaves the body through the urinary system. One of the commonest disorders seen in kidneys is nephrolithiasis, which refers to having minerals contained in urine crystallizing and accumulating in kidneys as stones. These stones may be as small as sand particles, or as large as golf balls. When moving into the ureters, the small ones may be discharged with urine and those having a diameter of several millimeters may clog the ureters and block urine discharge, causing intense loin pain that may sometimes extend to the hypogastrium or the groin.
One effective treatment for kidney stones is extracorporeal shock wave lithotrity, which only has minimal harm to the body and is usually non-hospitalizing. For the stones not fragmented by shock waves, a laparoscope treatment, i.e. using an ureterorenoscope, is typically effective. Only a small minority of patients need to be treated through the traditional open surgery as their stones are too large. Yet the traditional open surgery has its advantage that is ensuring the stones to be completely taken out.
The conventional extracorporeal shock wave lithotrity has the following shortcomings:
1. During the treatment, the real-time situation of stone fragmentation in the body is unavailable. The health care professional can only refer to X-ray or ultrasonic images before the operation to determine the size and location of the stones, and after a certain duration of operation, decide when to end the shock wave lithotrity depending on his/her experience.
2. During the treatment, the patient's kidneys and the stones therein can move as the patient breathes, bringing about uncertainty to the effect of the lithotripsy. In the event that the stone fragmentation is insufficient, the through-urethra discharge of the stones may fail, and causes additional pain and hydronephrosis to the patient.
For tracing kidney stones more effectively throughout the process of the shock wave lithotrity despite the displacement of the kidneys, the inventor of the present invention has invented a 3D ultrasonic image tracing system for extracorporeal shock wave lithotripters, which is now granted as Taiwan Patent No. 1414267. The prior-art invention involves building a patient's 3D ultrasonic stone image database in a computer system by using a 2D ultrasonic scanner to acquire ultrasonic image slices of the patient's stones and reorganizing theses 2D ultrasonic image slices. The 3D ultrasonic image database so built is then used as a reference database for the 3D tracing system. During the later lithotripsy treatment, the real-time 2D ultrasonic stone image slices are compared with the 3D ultrasonic stone image database for correlation analysis and location determining, so as to accurately focus the shock waves on the patient's stones and thereby ensure the effectiveness of the lithotripsy treatment. However, while the prior-art invention only proposes how to effectively trace the location of the stones in a patient's body, there is no mention about using the built 3D ultrasonic stone images for further analysis.